Bruce Power safely harvests Cobalt-60 from its Bruce B reactors during planned maintenance outages. The blue glow of the Cobalt-60 is called the ‘Cherenkov Effect’ and is a result of gamma radiation travelling through water faster than the speed of light travelling through water. When that occurs, photons are released, which creates the blue light. The Cobalt-60 is stored in water in the Secondary Fuel Bay until transported for processing. It is used then used to sterilize 40 per cent of the world’s single-use medical devices like syringes, sutures, and surgical gowns, masks and gloves.

One of the many activities completed as part of the Unit 8 maintenance program at Bruce Power was the removal of Cobalt-60 which will be processed by Nordion, an Ottawa-based company, for use in industrial irradiation applications worldwide.

Cobalt-60 irradiators are used to sterilize disposable medical supplies including sutures, syringes, surgical gowns and masks. Cobalt-60 is also used to sterilize pharmaceutical wares and cosmetics, and irradiate spices and other consumer products that include fruit, seafood, poultry and red meat. The $116 million routine maintenance and inspection program on Unit 8 began on Jan. 15 after more than 100 consecutive days of producing clean, low-cost and reliable electricity for Ontario businesses and families. The unit will return to service in the second quarter of 2016.

“Bruce Power is committed to playing a role in providing a reliable source of affordable, clean electricity over the long-term, while also helping to keep hospitals safe by providing the world’s largest source of Cobalt-60 from our Bruce B units,” said Len Clewett, Bruce Power’s Executive Vice President and Chief Nuclear Officer.

The World Health Organization (WHO) estimates more than 640,000 major surgeries are performed each day around the world and sterile disposable medical devices are used in virtually all of these procedures. Cobalt-60 is supplied to over 200 gamma irradiators in 55 countries.

How it works

Cobalt-60 can only be harvested when reactors are down during regularly scheduled maintenance.

Cobalt is mined like any other mineral. It’s removed from the ground and processed into pure Cobalt-59 powder, which is then compressed into slugs and coated with nickel. These slugs are then encapsulated and assembled into adjuster rods, which are used to control the reaction in Bruce Power’s reactors, where the cobalt is activated by absorbing neutrons to become Cobalt-60.

Bruce Power removes the rods during planned maintenance outages on the unit. The Cobalt-60 rods are then stored in Bruce Power’s secondary fuel bay, suspended on the bay wall about 14 feet below the surface. Specialized fuel handlers extract the Cobalt-60 rods one at a time, and place them in a shielded flask to be shipped to Nordion’s facility.

Once the bundles are received by Nordion, the Cobalt-60 is removed from its encapsulation and welded into a new double-encapsulated source called a C-188. It is then shipped to the sites of Nordion’s customers for use in irradiators.

Bruce Power operates the world’s largest operating nuclear generating facility and is the source of roughly 30 per cent of Ontario’s electricity. The company’s site in Tiverton, Ontario is home to eight CANDU reactors. Formed in 2001, Bruce Power is an all-Canadian partnership among Borealis Infrastructure Management (a division of the Ontario Municipal Employees Retirement System), TransCanada, the Power Workers’ Union and the Society of Energy Professionals. A majority of Bruce Power’s employees are also owners in the business.